On Wed, Oct 13, 2010 at 5:54 PM, Robert Haas robertmh...@gmail.com wrote:
Or to put it more bluntly - what is the problem with planner and hash
agg that all of these functions need to solve? And why does it need
a flag in pg_proc? Why can't't we leave it to the individual
functions to
On Wed, Oct 13, 2010 at 6:56 AM, Pavel Stehule pavel.steh...@gmail.com wrote:
2010/10/13 Pavel Stehule pavel.steh...@gmail.com:
2010/10/13 Peter Eisentraut pete...@gmx.net:
On mån, 2010-10-11 at 20:46 +0200, Pavel Stehule wrote:
The problem is in interface. The original patch did it, but I
2010/10/14 Robert Haas robertmh...@gmail.com:
On Wed, Oct 13, 2010 at 6:56 AM, Pavel Stehule pavel.steh...@gmail.com
wrote:
2010/10/13 Pavel Stehule pavel.steh...@gmail.com:
2010/10/13 Peter Eisentraut pete...@gmx.net:
On mån, 2010-10-11 at 20:46 +0200, Pavel Stehule wrote:
The problem is
On Wed, Oct 13, 2010 at 10:37 PM, Greg Stark gsst...@mit.edu wrote:
On Wed, Oct 13, 2010 at 5:54 PM, Robert Haas robertmh...@gmail.com wrote:
Or to put it more bluntly - what is the problem with planner and hash
agg that all of these functions need to solve? And why does it need
a flag in
Hello
I am looking on SQL standard for some info about within group
clause. This clause is necessary for functions:
rank, dense_rank, cume_dist, percent_rank and percentile_disc and
persentile_cont. These functions needs a clause WITHIN GROUP.
If I understand, then these functions are not
On mån, 2010-10-11 at 20:46 +0200, Pavel Stehule wrote:
The problem is in interface. The original patch did it, but I removed
it. We cannot to unsure immutability of some parameters now.
How about you store the immutable parameter in the transition state
and error out if it changes between
2010/10/13 Peter Eisentraut pete...@gmx.net:
On mån, 2010-10-11 at 20:46 +0200, Pavel Stehule wrote:
The problem is in interface. The original patch did it, but I removed
it. We cannot to unsure immutability of some parameters now.
How about you store the immutable parameter in the transition
2010/10/13 Pavel Stehule pavel.steh...@gmail.com:
2010/10/13 Peter Eisentraut pete...@gmx.net:
On mån, 2010-10-11 at 20:46 +0200, Pavel Stehule wrote:
The problem is in interface. The original patch did it, but I removed
it. We cannot to unsure immutability of some parameters now.
How about
2010/10/12 Hitoshi Harada umi.tan...@gmail.com:
2010/10/12 Pavel Stehule pavel.steh...@gmail.com:
Hello
2010/10/11 Greg Stark gsst...@mit.edu:
On Sun, Oct 10, 2010 at 2:16 PM, Tom Lane t...@sss.pgh.pa.us wrote:
It was pointed out upthread that while median isn't presently
in the standard,
2010/10/10 Tom Lane t...@sss.pgh.pa.us:
Dean Rasheed dean.a.rash...@gmail.com writes:
In the meantime, the attached variation of the patch fixes the temp
file issue and will support all 3 cases. It gives OK performance for
(1) and (2), and poor performance for (3). That could be viewed as a
On 10 October 2010 22:16, Tom Lane t...@sss.pgh.pa.us wrote:
It was pointed out upthread that while median isn't presently
in the standard, Oracle defines it in terms of percentile_cont(0.5)
which *is* in the standard. What I read in SQL:2008 is that
percentile_cont is defined for all numeric
2010/10/11 Dean Rasheed dean.a.rash...@gmail.com:
On 10 October 2010 22:16, Tom Lane t...@sss.pgh.pa.us wrote:
It was pointed out upthread that while median isn't presently
in the standard, Oracle defines it in terms of percentile_cont(0.5)
which *is* in the standard. What I read in SQL:2008
On 11 October 2010 10:55, Pavel Stehule pavel.steh...@gmail.com wrote:
BTW, why has percentile been removed from this patch? As the more
general, and SQL standard function, that would seem to be the more
useful one to include. Upthread it was mentioned that there is already
an ntile window
On Sun, Oct 10, 2010 at 5:16 PM, Tom Lane t...@sss.pgh.pa.us wrote:
It was pointed out upthread that while median isn't presently
in the standard, Oracle defines it in terms of percentile_cont(0.5)
which *is* in the standard. What I read in SQL:2008 is that
percentile_cont is defined for all
Dean Rasheed dean.a.rash...@gmail.com writes:
On 10 October 2010 22:16, Tom Lane t...@sss.pgh.pa.us wrote:
BTW, as far as the implementation issues go, telling tuplesort that it
can use gigabytes of memory no matter what seems quite unacceptable.
Put this thing into a hash aggregation and
Robert Haas robertmh...@gmail.com writes:
On Sun, Oct 10, 2010 at 5:16 PM, Tom Lane t...@sss.pgh.pa.us wrote:
It was pointed out upthread that while median isn't presently
in the standard, Oracle defines it in terms of percentile_cont(0.5)
which *is* in the standard. What I read in SQL:2008
On Mon, Oct 11, 2010 at 10:08 AM, Tom Lane t...@sss.pgh.pa.us wrote:
Robert Haas robertmh...@gmail.com writes:
On Sun, Oct 10, 2010 at 5:16 PM, Tom Lane t...@sss.pgh.pa.us wrote:
It was pointed out upthread that while median isn't presently
in the standard, Oracle defines it in terms of
On 11 October 2010 15:03, Tom Lane t...@sss.pgh.pa.us wrote:
Dean Rasheed dean.a.rash...@gmail.com writes:
On 10 October 2010 22:16, Tom Lane t...@sss.pgh.pa.us wrote:
BTW, as far as the implementation issues go, telling tuplesort that it
can use gigabytes of memory no matter what seems quite
Dean Rasheed dean.a.rash...@gmail.com writes:
On 11 October 2010 15:03, Tom Lane t...@sss.pgh.pa.us wrote:
Reflecting on it, I think it'd be best to allow an agg to
provide an estimation function that'd be told the input data type and
expected number of rows --- even on a per-aggregate basis,
On 11 October 2010 16:44, Tom Lane t...@sss.pgh.pa.us wrote:
Dean Rasheed dean.a.rash...@gmail.com writes:
On 11 October 2010 15:03, Tom Lane t...@sss.pgh.pa.us wrote:
Reflecting on it, I think it'd be best to allow an agg to
provide an estimation function that'd be told the input data type
Dean Rasheed dean.a.rash...@gmail.com writes:
The estimate of 200 x 8K is below work_mem, so it uses a hash
aggregate. In reality, each tuplesort allocates around 30K initially,
so it very quickly uses over 1GB. A better estimate for the aggregate
wouldn't improve this situation much.
Sure it
On 11 October 2010 18:37, Tom Lane t...@sss.pgh.pa.us wrote:
Dean Rasheed dean.a.rash...@gmail.com writes:
The estimate of 200 x 8K is below work_mem, so it uses a hash
aggregate. In reality, each tuplesort allocates around 30K initially,
so it very quickly uses over 1GB. A better estimate for
Dean Rasheed dean.a.rash...@gmail.com writes:
On 11 October 2010 18:37, Tom Lane t...@sss.pgh.pa.us wrote:
Sure it would: an estimate of 30K would keep the planner from using
hash aggregation.
Not if work_mem was 10MB.
And? If the memory requirement actually fits, you're in good shape.
On 11 October 2010 18:48, Tom Lane t...@sss.pgh.pa.us wrote:
Dean Rasheed dean.a.rash...@gmail.com writes:
On 11 October 2010 18:37, Tom Lane t...@sss.pgh.pa.us wrote:
Sure it would: an estimate of 30K would keep the planner from using
hash aggregation.
Not if work_mem was 10MB.
And? If
Dean Rasheed dean.a.rash...@gmail.com writes:
On 11 October 2010 18:48, Tom Lane t...@sss.pgh.pa.us wrote:
And? If the memory requirement actually fits, you're in good shape.
Yeah but the actual memory requirement, if it uses a hash aggregate,
is over 1GB, and could easily be much higher.
On 11 October 2010 19:05, Tom Lane t...@sss.pgh.pa.us wrote:
Dean Rasheed dean.a.rash...@gmail.com writes:
On 11 October 2010 18:48, Tom Lane t...@sss.pgh.pa.us wrote:
And? If the memory requirement actually fits, you're in good shape.
Yeah but the actual memory requirement, if it uses a
On Sun, Oct 10, 2010 at 2:16 PM, Tom Lane t...@sss.pgh.pa.us wrote:
It was pointed out upthread that while median isn't presently
in the standard, Oracle defines it in terms of percentile_cont(0.5)
which *is* in the standard.
Uhmm, then why don't we implement that? We could provide median() as
Uhmm, then why don't we implement that? We could provide median() as a
short-cut but percentile_cont() doesn't sound much harder to implement
than median() and more general.
I could really use percentile_cont(0.9), actually, for query
response-time analysis.
--
Hello
2010/10/11 Greg Stark gsst...@mit.edu:
On Sun, Oct 10, 2010 at 2:16 PM, Tom Lane t...@sss.pgh.pa.us wrote:
It was pointed out upthread that while median isn't presently
in the standard, Oracle defines it in terms of percentile_cont(0.5)
which *is* in the standard.
Uhmm, then why don't
2010/10/12 Pavel Stehule pavel.steh...@gmail.com:
Hello
2010/10/11 Greg Stark gsst...@mit.edu:
On Sun, Oct 10, 2010 at 2:16 PM, Tom Lane t...@sss.pgh.pa.us wrote:
It was pointed out upthread that while median isn't presently
in the standard, Oracle defines it in terms of percentile_cont(0.5)
Dean Rasheed dean.a.rash...@gmail.com writes:
In the meantime, the attached variation of the patch fixes the temp
file issue and will support all 3 cases. It gives OK performance for
(1) and (2), and poor performance for (3). That could be viewed as a
future development task, which perhaps the
2010/10/5 Dean Rasheed dean.a.rash...@gmail.com:
On 4 October 2010 18:22, Robert Haas robertmh...@gmail.com wrote:
On Mon, Oct 4, 2010 at 2:58 AM, Dean Rasheed dean.a.rash...@gmail.com
wrote:
That requires a new sort for each row. I generated this with a minor
tweak to Pavel's patch to just
On 5 October 2010 07:04, Hitoshi Harada umi.tan...@gmail.com wrote:
2010/10/5 Dean Rasheed dean.a.rash...@gmail.com:
On 4 October 2010 18:22, Robert Haas robertmh...@gmail.com wrote:
On Mon, Oct 4, 2010 at 2:58 AM, Dean Rasheed dean.a.rash...@gmail.com
wrote:
That requires a new sort for
2010/10/5 Dean Rasheed dean.a.rash...@gmail.com:
On 5 October 2010 07:04, Hitoshi Harada umi.tan...@gmail.com wrote:
Extrapolating from few quick timing tests, even in the best case, on
my machine, it would take 7 days for the running median to use up
100MB, and 8 years for it to use 2GB. So
On 5 October 2010 13:14, Hitoshi Harada umi.tan...@gmail.com wrote:
2010/10/5 Dean Rasheed dean.a.rash...@gmail.com:
On 5 October 2010 07:04, Hitoshi Harada umi.tan...@gmail.com wrote:
Extrapolating from few quick timing tests, even in the best case, on
my machine, it would take 7 days for the
2010/10/4 Greg Stark gsst...@mit.edu:
On Sun, Oct 3, 2010 at 7:06 AM, Hitoshi Harada umi.tan...@gmail.com wrote:
And I'm now thinking about how to make median happen in window
aggregate.
If you were to do this by extending tuplesort what extra features
would tuplesort need?
I don't think we
On 4 October 2010 07:36, Hitoshi Harada umi.tan...@gmail.com wrote:
2010/10/4 Greg Stark gsst...@mit.edu:
On Sun, Oct 3, 2010 at 7:06 AM, Hitoshi Harada umi.tan...@gmail.com wrote:
And I'm now thinking about how to make median happen in window
aggregate.
If you were to do this by extending
On Sun, Oct 3, 2010 at 11:58 PM, Dean Rasheed dean.a.rash...@gmail.com wrote:
The problem is that performance really sucks,
because it is an O(n^2 log(n)) algorithm. I don't see an easy way
around that without significant new infrastructure, as Greg describes,
or a completely different
On Mon, Oct 4, 2010 at 2:58 AM, Dean Rasheed dean.a.rash...@gmail.com wrote:
That requires a new sort for each row. I generated this with a minor
tweak to Pavel's patch to just restart the tuplesort each time (the
quick-fix solution). The problem is that performance really sucks,
because it is
On 4 October 2010 18:22, Robert Haas robertmh...@gmail.com wrote:
On Mon, Oct 4, 2010 at 2:58 AM, Dean Rasheed dean.a.rash...@gmail.com wrote:
That requires a new sort for each row. I generated this with a minor
tweak to Pavel's patch to just restart the tuplesort each time (the
quick-fix
2010/10/2 Pavel Stehule pavel.steh...@gmail.com:
Hello
updated version
* memsort removed
* window aggregate support blocked
I ran this patch and it looks good for committer.
Just one thing, in src/backend/utils/adt/Makefile median.o to compile
the new file is missing.
And I'm now thinking
On Sun, Oct 3, 2010 at 7:06 AM, Hitoshi Harada umi.tan...@gmail.com wrote:
And I'm now thinking about how to make median happen in window
aggregate.
If you were to do this by extending tuplesort what extra features
would tuplesort need?
Would tuplesort need the ability to insert additional
Hello
2010/10/3 Hitoshi Harada umi.tan...@gmail.com:
2010/10/2 Pavel Stehule pavel.steh...@gmail.com:
Hello
updated version
* memsort removed
* window aggregate support blocked
I ran this patch and it looks good for committer.
Just one thing, in src/backend/utils/adt/Makefile median.o
2010/9/26 Pavel Stehule pavel.steh...@gmail.com:
Hello,
there is updated version - with support of window clause. The limits
are work_mem for using inside window aggregate or unlimited when it is
used as standard query.
This patch needs a few work - can share a compare functionality with
Hello
2010/10/1 Hitoshi Harada umi.tan...@gmail.com:
2010/9/26 Pavel Stehule pavel.steh...@gmail.com:
Hello,
there is updated version - with support of window clause. The limits
are work_mem for using inside window aggregate or unlimited when it is
used as standard query.
This patch needs
Hitoshi Harada umi.tan...@gmail.com writes:
2010/9/26 Pavel Stehule pavel.steh...@gmail.com:
This patch needs a few work - can share a compare functionality with
tuplesort.c, but I would to verify a concept now.
Sorry for delay. I read the patch and it seems the result is sane. For
window
2010/10/1 Tom Lane t...@sss.pgh.pa.us:
Hitoshi Harada umi.tan...@gmail.com writes:
2010/9/26 Pavel Stehule pavel.steh...@gmail.com:
This patch needs a few work - can share a compare functionality with
tuplesort.c, but I would to verify a concept now.
Sorry for delay. I read the patch and it
2010/10/1 Tom Lane t...@sss.pgh.pa.us:
Hitoshi Harada umi.tan...@gmail.com writes:
2010/9/26 Pavel Stehule pavel.steh...@gmail.com:
This patch needs a few work - can share a compare functionality with
tuplesort.c, but I would to verify a concept now.
Sorry for delay. I read the patch and it
Hitoshi Harada umi.tan...@gmail.com writes:
2010/10/1 Tom Lane t...@sss.pgh.pa.us:
If this patch tries to force the entire sort to happen in memory,
it is not committable.
What about array_agg()? Doesn't it exceed memory even if the huge data come
in?
Yeah, but for array_agg the user
On Fri, Oct 1, 2010 at 10:11 AM, Hitoshi Harada umi.tan...@gmail.com wrote:
2010/10/1 Tom Lane t...@sss.pgh.pa.us:
Hitoshi Harada umi.tan...@gmail.com writes:
2010/9/26 Pavel Stehule pavel.steh...@gmail.com:
This patch needs a few work - can share a compare functionality with
tuplesort.c, but
2010/10/1 Tom Lane t...@sss.pgh.pa.us:
Hitoshi Harada umi.tan...@gmail.com writes:
2010/10/1 Tom Lane t...@sss.pgh.pa.us:
If this patch tries to force the entire sort to happen in memory,
it is not committable.
What about array_agg()? Doesn't it exceed memory even if the huge data come
in?
Hitoshi Harada umi.tan...@gmail.com writes:
Another suggestion?
The implementation I would've expected to see is to do the sort and then
have two code paths for retrieving the median, depending on whether the
sort result is all in memory or not.
regards, tom lane
--
Tom Lane t...@sss.pgh.pa.us wrote:
Hitoshi Harada umi.tan...@gmail.com writes:
Another suggestion?
The implementation I would've expected to see is to do the sort
and then have two code paths for retrieving the median, depending
on whether the sort result is all in memory or not.
Would it
2010/10/2 Tom Lane t...@sss.pgh.pa.us:
Hitoshi Harada umi.tan...@gmail.com writes:
Another suggestion?
The implementation I would've expected to see is to do the sort and then
have two code paths for retrieving the median, depending on whether the
sort result is all in memory or not.
Hm?
Hitoshi Harada umi.tan...@gmail.com writes:
2010/10/2 Tom Lane t...@sss.pgh.pa.us:
The implementation I would've expected to see is to do the sort and then
have two code paths for retrieving the median, depending on whether the
sort result is all in memory or not.
Hm? The problem we
2010/10/2 Tom Lane t...@sss.pgh.pa.us:
Hitoshi Harada umi.tan...@gmail.com writes:
2010/10/2 Tom Lane t...@sss.pgh.pa.us:
The implementation I would've expected to see is to do the sort and then
have two code paths for retrieving the median, depending on whether the
sort result is all in
2010/10/2 Kevin Grittner kevin.gritt...@wicourts.gov:
Tom Lane t...@sss.pgh.pa.us wrote:
Hitoshi Harada umi.tan...@gmail.com writes:
Another suggestion?
The implementation I would've expected to see is to do the sort
and then have two code paths for retrieving the median, depending
on
2010/10/1 Hitoshi Harada umi.tan...@gmail.com:
2010/10/2 Tom Lane t...@sss.pgh.pa.us:
Hitoshi Harada umi.tan...@gmail.com writes:
2010/10/2 Tom Lane t...@sss.pgh.pa.us:
The implementation I would've expected to see is to do the sort and then
have two code paths for retrieving the median,
Hello
updated version
* memsort removed
* window aggregate support blocked
Regards
Pavel
2010/10/1 Pavel Stehule pavel.steh...@gmail.com:
2010/10/1 Hitoshi Harada umi.tan...@gmail.com:
2010/10/2 Tom Lane t...@sss.pgh.pa.us:
Hitoshi Harada umi.tan...@gmail.com writes:
2010/10/2 Tom Lane
Hello,
there is updated version - with support of window clause. The limits
are work_mem for using inside window aggregate or unlimited when it is
used as standard query.
This patch needs a few work - can share a compare functionality with
tuplesort.c, but I would to verify a concept now.
Hello
2010/9/22 Hitoshi Harada umi.tan...@gmail.com:
2010/9/22 Pavel Stehule pavel.steh...@gmail.com:
Hello
I found probably hard problem in cooperation with window functions :(
tuplesort_begin_datum creates child context inside aggcontext. This
context is used for tuplestore. But when
Hello
I moved a median function to core.
+ doc part
+ regress test
Regards
Pavel Stehule
2010/9/20 Hitoshi Harada umi.tan...@gmail.com:
2010/8/19 Pavel Stehule pavel.steh...@gmail.com:
Hello
I am sending a prototype implementation of functions median and
percentile. This implementation
sorry
little bit fixed patch
Pavel
2010/9/23 Pavel Stehule pavel.steh...@gmail.com:
Hello
I moved a median function to core.
+ doc part
+ regress test
Regards
Pavel Stehule
2010/9/20 Hitoshi Harada umi.tan...@gmail.com:
2010/8/19 Pavel Stehule pavel.steh...@gmail.com:
Hello
I
2010/9/23 Pavel Stehule pavel.steh...@gmail.com:
Hello
2010/9/22 Hitoshi Harada umi.tan...@gmail.com:
2010/9/22 Pavel Stehule pavel.steh...@gmail.com:
Hello
I found probably hard problem in cooperation with window functions :(
maybe I was confused. I found a other possible problems.
The
2010/9/23 Hitoshi Harada umi.tan...@gmail.com:
2010/9/23 Pavel Stehule pavel.steh...@gmail.com:
Hello
2010/9/22 Hitoshi Harada umi.tan...@gmail.com:
2010/9/22 Pavel Stehule pavel.steh...@gmail.com:
Hello
I found probably hard problem in cooperation with window functions :(
maybe I was
On Thu, Sep 23, 2010 at 08:27:38PM +0200, Pavel Stehule wrote:
2010/9/23 Hitoshi Harada umi.tan...@gmail.com:
2010/9/23 Pavel Stehule pavel.steh...@gmail.com:
Hello
2010/9/22 Hitoshi Harada umi.tan...@gmail.com:
2010/9/22 Pavel Stehule pavel.steh...@gmail.com:
Hello
I found
2010/9/23 David Fetter da...@fetter.org:
On Thu, Sep 23, 2010 at 08:27:38PM +0200, Pavel Stehule wrote:
2010/9/23 Hitoshi Harada umi.tan...@gmail.com:
2010/9/23 Pavel Stehule pavel.steh...@gmail.com:
Hello
2010/9/22 Hitoshi Harada umi.tan...@gmail.com:
2010/9/22 Pavel Stehule
Hello
I found probably hard problem in cooperation with window functions :(
tuplesort_begin_datum creates child context inside aggcontext. This
context is used for tuplestore. But when this function is called from
WindowAgg_Aggregates context - someone drops all child context every
iteration,
On Tue, Sep 21, 2010 at 4:28 PM, Pavel Stehule pavel.steh...@gmail.com wrote:
* Cosmetic coding style should be more appropriate, including trailing
white spaces and indentation positions.
can you specify where, please?
I noticed a lot of problems in this area when working on your \ef /
\sf
2010/9/21 Robert Haas robertmh...@gmail.com:
On Tue, Sep 21, 2010 at 4:28 PM, Pavel Stehule pavel.steh...@gmail.com
wrote:
* Cosmetic coding style should be more appropriate, including trailing
white spaces and indentation positions.
can you specify where, please?
I noticed a lot of
2010/9/22 Pavel Stehule pavel.steh...@gmail.com:
2010/9/21 Robert Haas robertmh...@gmail.com:
On Tue, Sep 21, 2010 at 4:28 PM, Pavel Stehule pavel.steh...@gmail.com
wrote:
* Cosmetic coding style should be more appropriate, including trailing
white spaces and indentation positions.
can you
2010/9/22 Pavel Stehule pavel.steh...@gmail.com:
Hello
I found probably hard problem in cooperation with window functions :(
tuplesort_begin_datum creates child context inside aggcontext. This
context is used for tuplestore. But when this function is called from
WindowAgg_Aggregates context
2010/9/22 Hitoshi Harada umi.tan...@gmail.com:
2010/9/22 Pavel Stehule pavel.steh...@gmail.com:
2010/9/21 Robert Haas robertmh...@gmail.com:
On Tue, Sep 21, 2010 at 4:28 PM, Pavel Stehule pavel.steh...@gmail.com
wrote:
* Cosmetic coding style should be more appropriate, including trailing
2010/9/22 Hitoshi Harada umi.tan...@gmail.com:
2010/9/22 Pavel Stehule pavel.steh...@gmail.com:
Hello
I found probably hard problem in cooperation with window functions :(
tuplesort_begin_datum creates child context inside aggcontext. This
context is used for tuplestore. But when this
2010/8/19 Pavel Stehule pavel.steh...@gmail.com:
Hello
I am sending a prototype implementation of functions median and
percentile. This implementation is very simple and I moved it to
contrib for this moment - it is more easy maintainable. Later I'll
move it to core.
I've reviewed this
On Thu, Aug 19, 2010 at 11:59 AM, Pavel Stehule pavel.steh...@gmail.com wrote:
I am sending a prototype implementation of functions median and
percentile. This implementation is very simple and I moved it to
contrib for this moment - it is more easy maintainable. Later I'll
move it to core.
Greg Stark gsst...@mit.edu writes:
On Thu, Aug 19, 2010 at 11:59 AM, Pavel Stehule pavel.steh...@gmail.com
wrote:
I am sending a prototype implementation of functions median and
percentile. This implementation is very simple and I moved it to
contrib for this moment - it is more easy
On Thu, Aug 19, 2010 at 11:33 AM, Tom Lane t...@sss.pgh.pa.us wrote:
Greg Stark gsst...@mit.edu writes:
On Thu, Aug 19, 2010 at 11:59 AM, Pavel Stehule pavel.steh...@gmail.com
wrote:
I am sending a prototype implementation of functions median and
percentile. This implementation is very
On Thu, Aug 19, 2010 at 12:49:45PM -0400, Robert Haas wrote:
On Thu, Aug 19, 2010 at 11:33 AM, Tom Lane t...@sss.pgh.pa.us wrote:
Greg Stark gsst...@mit.edu writes:
On Thu, Aug 19, 2010 at 11:59 AM, Pavel Stehule pavel.steh...@gmail.com
wrote:
I am sending a prototype implementation of
David Fetter da...@fetter.org wrote:
Median may be useful, but we pretty much can't just call it
median. Instead, we need to call it something like left_median
or arithmetic_median.
I think it would be reasonable, and perhaps preferable, to use just
median for the semantics described in
On Thu, Aug 19, 2010 at 12:12:12PM -0500, Kevin Grittner wrote:
David Fetter da...@fetter.org wrote:
Median may be useful, but we pretty much can't just call it
median. Instead, we need to call it something like left_median
or arithmetic_median.
I think it would be reasonable, and
David Fetter da...@fetter.org writes:
On Thu, Aug 19, 2010 at 12:12:12PM -0500, Kevin Grittner wrote:
http://www.merriam-webster.com/dictionary/median
If you do a google search for median and poke around, you'll find
many places where this is the only definition mentioned; the others
seem
2010/8/19 David Fetter da...@fetter.org:
On Thu, Aug 19, 2010 at 12:49:45PM -0400, Robert Haas wrote:
On Thu, Aug 19, 2010 at 11:33 AM, Tom Lane t...@sss.pgh.pa.us wrote:
Greg Stark gsst...@mit.edu writes:
On Thu, Aug 19, 2010 at 11:59 AM, Pavel Stehule pavel.steh...@gmail.com
wrote:
I
2010/8/19 David Fetter da...@fetter.org:
On Thu, Aug 19, 2010 at 12:12:12PM -0500, Kevin Grittner wrote:
David Fetter da...@fetter.org wrote:
Median may be useful, but we pretty much can't just call it
median. Instead, we need to call it something like left_median
or arithmetic_median.
On Thu, Aug 19, 2010 at 01:25:36PM -0400, Tom Lane wrote:
David Fetter da...@fetter.org writes:
On Thu, Aug 19, 2010 at 12:12:12PM -0500, Kevin Grittner wrote:
http://www.merriam-webster.com/dictionary/median
If you do a google search for median and poke around, you'll find
many places
Pavel Stehule pavel.steh...@gmail.com wrote:
I looked there and Oracle11g use median in common sense.
As does Sybase IQ. FWIW, Excel spreadsheets do, too.
The chance of the SQL committee picking some other meaning for bare
MEDIAN seems vanishingly small; although I have to grant that with
David Fetter da...@fetter.org writes:
On Thu, Aug 19, 2010 at 01:25:36PM -0400, Tom Lane wrote:
A name like arithmetic_median seems much less likely to get
blindsided by future standardization.
Yep.
OTOH, if Pavel's right that Oracle already has an aggregate named
median(), it seems quite
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